<!DOCTYPE>
<html>
<head>
	<title></title>
	<meta charset="utf-8"/>
	<style>
		*{margin:0;padding:0}
		
		#div1{
			background:#50A3A2;
			position:absolute;
			left:0;
			top:50%;
			width:100%;
			height:400px;
			margin-top:-200px;
			overflow:hidden;
		}
		#div2{
			color:white;
			//background:grey;
			width:600px;
			height:400px;
			padding:80px 0;
			margin:0 auto;
			text-align:center;
		}
		#div2 h1{
			font-size:50px;
		}
		#div2 form{
			//border:1px solid red;
			padding:20px 0;
		}
		#div2 form input{
			//border:1px solid black;
			width:200px;
			padding:10px 0;
			display:block;
			margin:10px auto;
			border-radius:10px;
			font-size:15px;
			text-align:center;
		}
		#div2 form button{
			width:200px;
			color:green;
			font-size:20px;
			border-radius:15px;
		}
	</style>
</head>
<body>
	<div id="div1">
		<div id="div2">
			<h1>welcome</h1>
			<form action="" method="get">
				<input type="text" name="userid" placeholder="请输入用户名"/>
				<input type="password" name="userpw" placeholder="请输入密码"/>
				<button type="submit" />登&nbsp;&nbsp;录</button>
			</form>
		</div>
	</div>
</body>
</html>